EFFECT OF PRESSURE ON THE RAMAN DEPOLARIZATION RATIO AND THE VIBRATIONAL-RELAXATION OF THE V1 MODE OF LIQUID CARBON-TETRACHLORIDE AT 22-DEGREES-C AND 0-1.1 KBAR

The depolarization ratio of the nu-1 Raman bands and the vibrational relaxation time of liquid carbon tetrachloride at 1 bar to 1.1 kbar were obtained by resolving the overlapping nu-1 fundamental bands of five isotopic species and three broad combination bands by least-squares fitting. The eight component bands were represented by Voigt functions, the Gaussian widths of which were determined from the spectral slit widths. The resulting depolarization ratio of the nu-1 fundamental bands at 1 bar is 0.0040, which is about 40% smaller than the depolarization ratio obtained from the whole region of the nu-1 band. It decreases to 0.0033 at 1.15 kbar, which follows approximately the theoretical curve of the fluctuating-local-field model. The vibrational relaxation time obtained from the band width of the nu-1 fundamental band of C35Cl4 decreases linearly from 6.0 ps at 1 bar to 4.7 ps at 1.15 kbar. The change is well reproduced by Schweizer and Chandler's kinetic model.